With fluorescent tube – can also light tube from PLASMA (a state of matter – charged gas? …..?) ball and where you hold tube determines how much it will light!
Only cobalt, iron and nickel and their compounds are magnetic???!!!
Magnetic field lines
Making a compass – stroke a nail (steel or iron) with neodinium or ceramic magnets and place on a large flat cork in a tray of water – should align with earth’s poles
Right – hand curl rule
Can build up a bride of iron filings by adding amounts to each pole of a large magnet
Due to currents
Compasses around single core wire (within circuit)
Magnetic force on a current (moving charge)
Making D.C. motors
Single core wire (in a circuit) in a strong magnetic field
Jumping ring
Fleming’s left hand rule
Electromagnetic induction – a.c. and dynamo appears in too many places
Induced electromotive force (induced emf)
Dynamo
Michael Faraday
Lenz’s law
Alternating Current – see a.c. in current topic
A.C. generator (a motor connected to a D.C. supply will turn; replace D.C. supply with an oscilloscope and manually turn the coils, will produce an A.C. – see dynamo above)
dynamo
Transformers
Power losses in transmission (less power lost at high voltage – power lines)
Power lines demonstration
Show that uses A.C., in primary coil to produce a changing magnetic field through the core that induces a current (that will be A.C.) in secondary coil
Eddy currents & electromagnetic breaking
Swinging aluminium vane
Effects of changing aluminium thickness vs. breaking force (I.B. project: air track with runner mounting aluminium vane that moves through a strong magnetic field (horse shoe magnet)– light gates both ends of the magnet measure change in speed of runner.
Fields
Electromagnetic induction – a.c. and dynamo appears in too many places